Ludwig managing to trick and subdue Beef before spending most of the first half of the story disguised as him. He definitely earns his title as the most intelligent of the Koopalings.
Roy gets an offscreen one given that he fought his way past hordes of minions infected with Malatone Formula X. By the time the Koopa Troop catches up with him, he's left piles of minions unconscious in his wake (though he finally passes out from exhaustion shortly afterwards).
Captain Goomba and his trio of captains coming to the rescue of Bowser Jr when he's defeated by the BFF. When their leader needs them the most, they come through and deliver. And just like before, they manage to fight off the BFF just long enough for Junior to get back on his feet and rally the army to victory.
Bowser Jr.'s speech to the BFF right before the final battle. Dieter asks him if Bowser and his army is evil, and after initially struggling to find an answer, he responds that good and evilare outdated terms and questions if it's wrong for him to help his father conquer the Mushroom Kingdom. The kid's been through quite a lot of crap to get to where he was, and that moment cemented him as the future king of Bowser's domain.
